Flameproofing composition



' I SEARCH Room UNE'EED STATES PATENT @FFECE FLAMEPROOFING COBEPOSITION Charles M. Albion, Boston, Mass, asslgnor to FQR Herbert B. Morse, Wellesley, Mass.

No Drawing. Application May 12, 1937, Serial No. 142,314

6 Claims. (Cl. 106-31) The present invention relates to compositions suitable for coating insulated conductors I give for the preventionooiflame-propagatign in infiamthe following:

mable materials such as the insulationb'f' electri Parts cal conductors, nonmetallic conduits for such A p alt 100 conductors, prepared roof coverings, and for C orinated lime l5 5 other like and analogous goods and purposes. ax 7to10 It comprises the combination (in the legal sense The asphalt here referred to is that which is of that term) with a foundation coating or imcommonly used for impregnating the braided or pregnflting substance, Such as asphalt coal woven coverings of insulated wires, noninetallic 10 or a wax (natural or synthetic), of a substance electrical conduits. roofingvfelts and paper em 10 capable f generating an inert fire W In place of chlorinated lime, hexachlorethane 39.8 whe heated, and a non'combustlblc or other chlorinated hydrocarbon may be substi- Stance Which is fusible by the heat of a flame tuted; and in place of borax silicate of soda may briefly app and solidifies on cooling a be substituted. Chlorinated lime and hora-x, or 1 hard continuous b y- D their equivalents, may also be used in the same A part of my O je is to produce a Composltlon or other proportions with coal tar or with various Which can be made at small expense and S to waxes in place of asphalt. Or if desired, borax the use of indus y at low cost; and one which and silicate of soda may be used together. The at the same time is substantially non-absorptive content f borax and/Or Silicate f soda is of water and not subject to oxidation. While vided in the Solid pulverized fornm The Chorim flameproofing substa Compounds and ated lime, when used, is likewise finely divided; tures are known, so of which are highly and so is any. solid chlorinated hydrocarbon which cient considered from lZho point of View Of flame" may be used in place of chlorinated lime. These pr fi alone, yet those which are most effioienl' ingredients, or any two of them, are added to the in this particular are high in 60st, and some are base composition of asphalt, wax or coal tar when unsatisfactory also by reason of Propensity to the latter is in liquid condition, or rendered so by absorb water and to combine with oxygen when heat and thoroughly mixed by any Suitable v Q heated to the melting point. means. if? As the gas generating ingredient i my oompo- A wide variation in the base ingredient (i. e.,

g7 sition I use preferably a chlorinated hydrocarbon asphalt, t or waxes) and in t proportions of 30 H or chlorinated lime. These substances contain the other ingredients may be used according as lar p p al contents of chlorine gas Which it is desired to control the melting' point of the is libera ed unde he application instance, composition and to furnish compositions which chlorinated lim produced y pa chlorine penetrate more or less readily among the fibers gas t h slakeci or (p ef r ly) un e l of braided, Woven or felted fabrics. If the ccmy Contain in absorbed Condition as much as position is to be used as a nonpenetrating coating from 35% to of C n Many hyd o outside of an impregnated web or felt, a solid bons, both solid and liquid, may be chlorinated hydrocarbon or chlorinated lime is used as the to like eilect. As an example of a solid chlorisource of the quenc fl a pr p 40 nated hydrocarbon which is suitame for m tion of the chlorinated lime and borax, or their pose and which I have used to good cfiect, I may equlvalems a be used if it Fl ig mention hexachlorethane. But many other hy-- the memng t of the zt q Dmerent drocarbons capable of absorbing or combining g zf i gfi t t l g the 4.5 with chlorine and of one choose as who tttliiid fiishstitiitifititthyiiliii heated known 9 chemlsts' hi may be or smaller contents of the other ingredients. used f thls {Jurpose m my composmon- Where it is desired to saturate woven or braided Suitable fusible substances are borax and solid cqveyings nduit, roofing felt or paper, etc, coal silicate of soda. hose substances melt under tar may be substituted for asphalt, or a wax or the heat of a flame and solidify into a condition mixture of waxes having a desired melting point 00 resembling gloss. ir function in h p tray be used; and a liquid chlorinated hydrocarsiiion is to form on ihoruStai-ion. or s s th hon may be substituted for the solid chlorine abgas which is evolved from the chorlnated lime or sorber. I propose to make use of the aiailable y fi i H knowledge concerning waxes, natural and syn- N As an illustrative example of a composition thetlc, their melting pointsgand the inciting of asphalt, having any prescribed or desired melting temperature. 1

It will be apparent from the foregoing that the specific ingredients and proportions named in the illustrative example are not narrowly limiting as to the scope of the protection which I seek.

The preparations conforming to this invention are applied to insulated wires, conduits, roofing sheets, etc., in the same manner that waterproofing and fireproofing impregnants and coatings have been used heretofore, or in any other way which may be found suitable for the purpose.

When an insulated wire coated with the composition hereinbefore described is subjected to the flame test prescribed by the fire underwriters, the coating liquefies and bubbles. The bubbles are caused by gas evolved from the chlorinated lime, and are imprisoned by the shell or incrustation formed by the borax or silicate of soda. So that on removal from the flame, the coating is found to be a mass of cells or bubbles of which the walls are fixed and made solid by the content of borax or silicate of soda and the interiors are filled with chlorine. effect on fiame and prevents propagation of fire along the inflammable insulation from a point of origin. Thus it prevents spreading of fire in electrical insulation caused by a short circuit. And it has a like effect in preventing the spread of flame from sparks on roofing material. Being much heavier than air, such of it as may escape from the confining walls of the bubbles forms a blanket over subjacent surfaces (such as root surfaces), extinguishing or helping to extinguish sparks and fire brands at other points.

In its broader aspects the invention is not limited to substances which liberate chlorine on being heated, but includes within the scope of equivalents other materials which in like conditions will liberate other heavy inert gases. But from the commercial aspect, the carriers of liberatable Chlorine gas has an active quenching nfnated hydrocarbon chlorine are preferable to those of other gases on account of their availability and low cost, and of these chlorinated lime, being particularly plentiful and cheap in price, as well as otherwise satisfactory, is preferable to others.

What I claim and desire to secure by Letters Patent is:

1. A composition of matter as and for the purposes hereinbefore described, consisting of a. water-repellent material selected from the group consisting of asphalt, coal tar and wax, an inert substance carrying chlorine adapted to liberate chlorine when heated, and a heat fusible substance selected from the group consisting of borax and silicate of soda.

2. A composition of matter as and for the purposes hereinbefore described, consisting of a water-repellent material selected from the group consisting of asphalt, coal tar and wax, chlorinated lime, and a heat fusible substance selected from the group consisting of borax and silicate of soda.

3. A composition of matter as and for the purposes hereinbefore described, consisting of a water-repellent material selected from the group consisting of asphalt, coal tar and wax,

M and a substance selected from the group consisting of borax and silicate of soda.

4. A composition of matter as and for the purposes hereinbefore described, consisting of a water-repellent material selected from the group consisting of asphalt, coal tar and wax, chlorinated lime, and borax.

5. A composition of matter as and for the purposes hereinbefore described, consisting of a water-repellent material selected from the group consisting of asphalt, coal tar and wax, chlorinated lime, and silicate of soda.

6. A composition of matter for the purposes set forth, consisting of asphalt, chlorinated lime and borax.

CHARLES M. ALBION. 

